1. Field of the Invention
The present invention relates to a module for transmitting and receiving optical signals through optic fibers, and, more particularly, to a coupling module having a detachable electrical connector for coupling electrical signals to the module.
2. Description of the Prior Art
Increasingly, the technical progress of computer systems requires massive data transmission at high transmission rates to computer peripherals such as monitors, hard discs, printers, and the like. Additionally, the development of the internet accelerates the need for high-speed connections between computer systems so as to lead to a trend of high speed data transmission between separate computer systems.
In responding to this trend, data transmission with existing electrical wires reveals limitations in electrical cabling, including the bandwidth limitations of electrical wires and the effects of electromagnetic wave interference in transmission signals characteristic of high data transmission rates. Accordingly, in order to overcome the limitations of such electric signal transmission, the data transmission field is increasingly looking towards optical signal transmission methods using optical fiber for high rate data transmission.
Optical transmission of data at high transmission rates has several advantages. For example, optical fibers provide higher bandwidth data transmission at lower error rates without the electromagnetic interference inherent in adjacent electrical transmission lines, overcoming two of the primary problems of data transmission over electrical cabling. Complementary optical signal transceiver modules, then, easily cope with the parallel data transmissions that are desirable in many computer system applications.
Conventional parallel optical signal transceiver modules have detachable optical connectors with fixed electrical connections to an external electric circuit. However, the detachable optical connector must have a structure allowing connections and separations. Due to alignment problems inherent in manufacture and in aging of the connector, these connections can become unstable so that the coupling of optical data into or out of the optical fibers is degraded. Such unstable connections may cause the loss or the transformation of transmission data, which is a serious drawback to an optical connector requiring a high reliability of optical data transmission. In addition, the connection part of the detachable optical connector can become polluted with pollutants such as dust and other contaminates, which may also degrade the transmission of optical signals.
One approach to the alignment problem is to more rigidly support the connector part to provide better alignment to the optical fibers. However, this approach increases the size of the connector. As the size of the optical connection part gets larger, the entire system which utilizes the optical connector gets larger as well. The larger size of a system deteriorates space utility efficiency, leading to a reversal in the miniaturization trend, and therefore is an undesirable result. For example, the miniaturization of electrical circuit components built in an electric circuit board lowers the height of the built-in electric circuit components to about 1xcx9c2 mm levels from the surface of the electric circuit board, but the height of the conventional optical parallel transceiver module becomes about 1 cm, leading to a difficulty in miniaturizing systems requiring optical connections.
Therefore, there is a need for optical transceiver modules having small form factors that do not suffer the degradation of optical transmission due to alignment or contamination.
In accordance with the present invention, an optical transceiver system having a detachable electrical connection is presented. Because an electrical connection is detached, rather than the optical connection as is conventional, an optical transceiver system in accordance with the present invention does not suffer from contamination of the optical components or from degradation of the optical alignment due to repeated attaching and detaching operations. Additionally, embodiments of an optical transceiver system in accordance with the present invention can have small form factors in conformity with the about 1 to about 2 mm height of the external circuitry to which the transceiver system is coupled.
In some embodiments, a miniaturized optical transceiver module according to the present invention comprises an electrical connector for coupling an electric signal between an external circuit board and the miniaturized optical transceiver module; an optical device array detachably coupled to the electrical connector so that electrical signals are transmitted between the electrical connector and optical devices in the optical device array; and an optical fiber array block fixedly mounted in the optical device array block so that optical fibers of the optical fiber array are optically coupled to the optical devices of the optical device array. In some embodiments, the electrical connector is fixed on the external circuit board. In some embodiments, an optical device array includes any number of light emitters and optical detectors. In some embodiments, the optical device array includes either light emitters or optical detectors.
These and other embodiments are further described below with respect to the following figures.